<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <!-- 省市二级联动 -->
    <select >
        <option>--请选择省份--</option>
        <option value="" selected="selected">北京</option>
        <option value="">上海</option>
        <option value="">深圳</option>
        <option value="">武汉</option>
    </select>

    <select>
        <option>--请选择城市--</option>
        <option value="" selected="selected">海定区</option>
        <option value="">浦东区</option>
        <option value="">龙岗</option>
        <option value="">武汉</option>
        <option value=""></option>

    </select>
</body>
</html>